U.S. patent application number 13/031158 was filed with the patent office on 2012-02-23 for photography led lighting and effects generation system.
Invention is credited to Kevin C. Baxter, Ken Fisher, Pat Grosswendt, Fred H. Holmes, RUDY G. POHLERT.
Application Number | 20120044374 13/031158 |
Document ID | / |
Family ID | 43920305 |
Filed Date | 2012-02-23 |
United States Patent
Application |
20120044374 |
Kind Code |
A1 |
POHLERT; RUDY G. ; et
al. |
February 23, 2012 |
PHOTOGRAPHY LED LIGHTING AND EFFECTS GENERATION SYSTEM
Abstract
A lighting apparatus comprises a light panel having a panel
frame, and a plurality of LEDs or other light elements secured to
the panel frame. The panel frame may be a portable frame. A
self-contained battery unit securably attaches to the outside of
the panel frame. The light panel may have a dimmer switch, and may
also be capable of receiving power from a source other than the
self-contained battery unit. The lighting apparatus can be mounted
to a camera or a stand. The lighting apparatus may include an
effects generator in communication therewith which generates a
continuous light or a flash of light from the LEDs or other light
elements. Diffusion lenses or color gels may be integrated with or
detachable from the light panel.
Inventors: |
POHLERT; RUDY G.;
(CALABASAS, CA) ; Grosswendt; Pat; (Agoura,
CA) ; Fisher; Ken; (North Hollywood, CA) ;
Baxter; Kevin C.; (Glendale, CA) ; Holmes; Fred
H.; (Cleveland, OK) |
Family ID: |
43920305 |
Appl. No.: |
13/031158 |
Filed: |
February 18, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61306433 |
Feb 19, 2010 |
|
|
|
Current U.S.
Class: |
348/220.1 ;
315/193; 348/370; 348/E5.024 |
Current CPC
Class: |
H04N 5/2256 20130101;
H04N 5/23245 20130101 |
Class at
Publication: |
348/220.1 ;
348/370; 315/193; 348/E05.024 |
International
Class: |
H04N 5/225 20060101
H04N005/225; H05B 37/02 20060101 H05B037/02 |
Claims
1. A camera illumination system for image capture, comprising: (a)
a camera having at least a video mode and a still picture mode; (b)
at least one LED in electronic communication with said camera, said
at least one LED illuminating at least a portion of a field of view
of said camera when said LED is activated; and (c) control
circuitry in electronic communication with said LED and with said
camera, said control circuitry at least for activating said at
least one LED to a strobe mode when said camera is in said still
picture mode and a continuous illumination mode when said camera is
in said video mode.
2. The camera illumination system for image capture according to
claim 1, wherein said at least one LED comprises a plurality of
LEDs arranged in an array.
3. The camera illumination system for image capture according to
claim 1, wherein said control circuitry comprises: (1) a sync
connector in electronic communication with said camera, (2) a
microprocessor in electronic communication with said sync connector
and with said at least one LED, said microprocessor being
programmed to at least activate said LED to a strobe mode or to a
continuous illumination mode in response to a signal from said sync
connector.
4. The camera illumination system for image capture according to
claim 1, wherein said at least one LED is removably attached to
said camera.
5. The camera illumination system for image capture according to
claim 1, wherein said camera is selected from a group consisting of
a digital still camera, a film camera, a video camera, a motion
picture camera, a photography camera, and a digital video
camera.
6. An area illumination system, comprising: (a) at least one LED;
and, (b) circuitry in electronic communication with said LED, said
circuitry at least for activating said LED in either a strobe mode
or a continuous mode.
7. The area illumination system according to claim 6, wherein said
at least one LED comprises a plurality of LEDs arranged in an
array.
8. The area illumination system according to claim 6, wherein said
at least one LED comprises a linear LED array.
9. The area illumination system according to claim 6, wherein said
control circuitry comprises: (1) a sync connector in electronic
communication with said camera, (2) a microprocessor in electronic
communication with said sync connector and with said at least one
LED, said microprocessor being programmed to at least activate said
LED to either a strobe mode or to a continuous illumination mode in
response to a signal from said sync connector.
10. The area illumination system according to claim 6, wherein said
at least one LED is removably attached to a camera.
11. The camera illumination system for image capture according to
claim 10, wherein said camera is selected from a group consisting
of a digital still camera, a film camera, a video camera, a motion
picture camera, a photography camera, and a digital video
camera.
12. An area illumination system for lighting a subject for film,
photography or video, the illumination system comprising: (a) a
portable frame, said portable frame adapted for temporary mounting
to a movable camera apparatus such that said portable frame follows
the movements of the camera apparatus, said portable frame being
readily detachable from the camera apparatus; (b) a plurality of
LEDs arranged in a plurality of linear rows across a front face of
said frame for lighting the subject for film, photography, or
video; and, (c) an effects generator which is configurable to
activate said LEDs in at least two different modes, wherein said at
least two different modes comprise a first mode that generates a
flash of light from said plurality of LEDs and a second mode that
generates a continuous light from said plurality of LEDs.
13. The camera illumination system for image capture according to
claim 12, wherein said camera is selected from a group consisting
of a digital still camera, a film camera, a video camera, a motion
picture camera, a photography camera, and a digital video
camera.
14. The camera illumination system for image capture according to
claim 12, wherein said effects generator comprises: (1) a sync
connector in electronic communication with said camera, (2) a
microprocessor in electronic communication with said sync connector
and with said at least one LED, said microprocessor being
programmed to at least activate said LED to a strobe mode or to a
continuous illumination mode in response to a signal from said sync
connector.
15. An area illumination system for lighting a subject for film,
photography or video, the illumination system comprising: (a) a
portable frame, said portable frame adapted for temporary mounting
to a movable camera apparatus such that the portable frame follows
the movements of the camera apparatus, said portable frame being
readily detachable from the camera apparatus; (b) a plurality of
LEDs secured to said frame for lighting the subject for film,
photography, or video; (c) a dimmer integrated with said portable
frame, said dimmer configured to provide manual adjustment of an
illumination intensity of said light emitting diodes; and (d) an
effects generator which is configurable to activate said LEDs in at
least two different modes, wherein said at least two different
modes comprise a first mode that that generates a flash of light
from said plurality of LEDs and a second mode that generates a
continuous light from said plurality of LEDs.
16. An area illumination system for lighting a subject for film,
photography or video, the illumination system comprising: (a) a
frame, said frame adapted for being mounted to and readily
disengaged from a stand, a plurality of light emitting diodes
(LEDs) arranged across a front face of said frame for lighting the
subject for film, photography, or video; and (b) an effects
generator which is configurable to activate said LEDs in at least
two different modes, wherein said at least two different modes
comprise a first mode that that generates a flash of light from
said plurality of LEDs and a second mode that generates a
continuous light from said plurality of LEDs.
Description
RELATED CASES
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 61/306,433 filed on Feb. 19, 2010 and
incorporates said provisional application by reference into this
disclosure as if fully set out at this point.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The field of the present invention relates to lighting
apparatus and systems as may be used in photography, film,
television, and other applications.
[0004] 2. Background
[0005] Lighting systems are an integral part of the film and
photography industries. Proper illumination is essential when
filming movies, television shows, or commercials, when shooting
video clips, or when taking still photographs, whether such
activities are carried out indoors or outdoors. In some instances,
an illumination effect may also be desired for live performances on
stage or in any other type of setting.
[0006] Historically, camera systems were designed for either video
or still photography. The associated lighting systems were likewise
categorized such that lighting systems for film, television or
video were not necessarily suitable lighting systems for still
photography. The principal difference between such lighting systems
is that lighting that is intended for video shines continuously
once activated, whereas lighting for photography is pulsed
(strobed, flashed, etc.) in synchronization with the shutter of a
camera to take a picture.
[0007] The emergence of digital photography has changed the camera
industry dramatically. However, corresponding changes in the
lighting industry have been slow to appear. For example, advances
in technology have substantially blurred the distinctions between
still and video photography. Modern video cameras are equipped to
capture still images. Likewise digital SLR cameras are now capable
of professional quality video image capture. Photographers who are
present at news and sporting events now can use a single camera to
capture both still images and video (including HD video) that is
suitable for use in print (or on-line) publications. The video
obtained by such cameras is suitable for use on broadcast
television and/or for on-line access. Indeed, the video from such
cameras is increasing being used in network and other news
broadcasts in instances where there are no news crews on the ground
and, thus, no other source of first person event coverage. However,
the lighting system for such cameras is still wedded to separate
systems for photograph and video. A need, therefore exists for a
lighting system which is suitable for the demands of both video
capture and still photography image capture.
[0008] In more particular, professional still photography has
heretofore required the use of large lights that are situated on
stands and that require access to a power supply that is most
commonly supplied via a cord or cable. These lights and stands are
typically heavy and require time to move into the studio and to
position for a shoot. As a result spontaneous setup and use of such
system is not feasible. This is particularly so in environments
where spectators and others could trip over the cords/cables. Thus,
a need also exists for a lighting and effects system which is
portable and self powered to provide rapid setup, even in crowded
environments.
[0009] A primary purpose of a lighting system is to illuminate a
subject to allow proper image capture or achieve a desired effect.
Often it is desirable to obtain even lighting that minimizes
shadows on or across the subject. It may be necessary or desired to
obtain lighting that has a certain tone, warmth, or intensity. It
may also be necessary or desired to have certain lighting effects,
such as colorized lighting, strobed lighting, gradually brightening
or dimming illumination, or different intensity illumination in
different fields of view.
[0010] Various conventional techniques for lighting in the film and
television industries, and various illustrations of lighting
equipment, are described, for example, in Lighting for Television
and Film by Gerald Millerson (3rd ed. 1991), hereby incorporated
herein by reference in its entirety, including pages 96-131 and
295-349 thereof, and in Professional Lighting Handbook by Verne
Carlson (2nd ed. 1991), also hereby incorporated herein by
reference in its entirety, including pages 15-40 thereof.
[0011] As one example illustrating a need for an improved lighting
effects system, it can be quite challenging to provide proper
illumination for the lighting of faces in still photography,
especially for situations where close-up photographs are required.
Often, certain parts of the face must be seen clearly. In addition,
a need exists for such an effects lighting system that can be
adapted for lightweight, battery powered operation as often
required by still photographers.
[0012] The most common lighting systems in film, commercial, and
photographic settings use either incandescent, fluorescent, or gas
discharge light elements. However, conventional lighting systems
have certain well known drawbacks or limitations which can limit
their flexibility or effectiveness. Chief among their limitations
are that because of their custom nature, both incandescent lighting
systems and fluorescent lighting systems can be difficult to adapt
to different or changing needs of a particular film project or
shoot. For example, if the photographer decides that a different
lighting configuration should be used, or wants to experiment with
different types of lighting, it can be difficult, time-consuming,
and inconvenient to re-work or modify the customized lighting
setups to provide the desired effects. Furthermore, both
incandescent lighting systems and fluorescent lighting systems are
generally designed for placement off to the side of the camera,
which can result in shadowing or uneven lighting.
[0013] A variety of lighting apparatus have been proposed for the
purpose of inspecting objects in connection with various
applications, but these lighting apparatus are generally not
suitable for the movie, film or photographic industries. For
example, U.S. Pat. No. 5,690,417, hereby incorporated herein by
reference in its entirety, describes a surface illuminator for
directing illumination on an object (i.e., a single focal
point).
[0014] LED-based lighting apparatus have been developed for various
live entertainment applications, such as theaters and clubs. These
lighting apparatus typically include a variety of colorized LEDs in
hues such as red, green, and blue (i.e., an "RGB" combination), and
sometimes include other intermixed bright colors as well. These
types of apparatus are not well suited for applications requiring
more precision lighting, such as film, television, and so on. Among
other things, the combination of red, green, and blue (or other)
colors creates an uneven lighting effect that would generally be
unsuitable for most film, television, or photographic applications.
Moreover, most of these LED-based lighting apparatus suffer from a
number of other drawbacks, such as requiring expensive and/or
inefficient power supplies, incompatibility with traditional AC
dimmers, lack of ripple protection (when connected directly to an
AC power supply), inaccurate production of "white" light, and lack
of thermal dissipation.
[0015] In the context of film and television, various attempts have
been made to develop camera-mounted lighting fixtures; however,
prior attempts to provide a suitable camera-mounted lighting
fixture suffer from a variety of potential drawbacks. For example,
conventional camera-mounted lighting fixtures using incandescent,
gas discharge, or fluorescent lighting elements suffer from the
same drawbacks as described above, and can cause undesirable
shadowing or other side effects. Also, camera-mounted lighting
fixtures which are designed to connect to the camera's battery can
cause premature depletion of the battery. Other lighting fixtures
are designed to be powered by a battery pack that is worn,
typically on a belt, by the camera operator. Such battery belts are
often heavy and cumbersome, and may require lengthy power cords
that can interfere with camera maneuverability. Additionally, prior
art camera-mounted light units have been proven to be a burning
hazard since they are mounted in such close proximity to the camera
operator and they can become very hot during operation. Accidental
contact with the camera during operations or handling carries a
risk of dealing a painful burn to the victim.
[0016] It would therefore be advantageous to provide a lighting
apparatus or lighting effects system that is versatile and
portable, and may find use in a variety of applications. It would
further be advantageous to provide a lighting apparatus or lighting
effects system that is well suited for use in the film, commercial,
and/or photographic industries, and/or with live stage
performances, that overcomes one or more of the foregoing
disadvantages, drawbacks, or limitations.
SUMMARY OF THE INVENTION
[0017] Applicant incorporates herein by reference U.S. Pat. No.
7,429,117 as if fully set out at this point.
[0018] The invention is generally directed in one aspect to a novel
and versatile lighting apparatus and effects generator. According
to one embodiment as disclosed herein, a preferred lighting
apparatus configuration comprises a light having a panel frame,
with a plurality of semiconductor light elements, such as LEDs,
secured to the panel frame. A self-contained battery unit may be
attached to the panel frame. In some preferred embodiments the
battery unit might be removable from the panel frame and in other
embodiments it might be incorporated into (e.g., made a part of)
the panel frame or the camera body. Additionally, it should be
noted that the battery pack might be a single purpose or customized
device suitable for a particular camera or a more conventionally it
might be a compartment into which one or more standard batteries
(e.g., A, AA, C, etc.) might be placed. When attached together, the
light panel and self-contained battery unit function as an
integrated lighting apparatus. Optionally, the light panel may have
an integrated dimmer switch, and may also be capable of receiving
power from a source other than the self-contained battery unit.
[0019] The instant lighting and effects apparatus may be mounted to
a video or still camera, where the term "mounted" should be broadly
construed to include instances where the lighting and effects
apparatus are removably mounted as well as instances where the
lighting apparatus is integral to the associated camera.
Alternatively it may be mounted to a stand or tripod.
[0020] The lighting apparatus and effects generator of the instant
invention is suitable for providing continuous illumination for a
subject during video photography. The continuous illumination is
also particularly suited as a modeling light for still photography.
Furthermore, when a burst of light such as a flash or strobe is
required, the lighting apparatus is capable of generating this
required effect in a burst mode, preferably in synchronization with
a shutter of a still or other camera. The lighting apparatus may
also be dimmable in both the continuous or burst mode operation. As
such, the lighting and effect generator of the present disclosure
is suitable for video capture and/or still photography or the
combination of both. In addition the light emitted may be shaped or
color balanced as desired. Accordingly, continuous illumination is
for modeling and a burst mode for flash or strobe is accomplished
in the same light emitter in the same color balance (same quality
of light).
[0021] The lighting and effects system of the present disclosure
will also be preferably capable of providing aperture portion
control. Additionally, the preferred embodiment of the instant
lighting and effects system will be capable of F-stop control
through an input signal to its microprocessor. Further, through the
lens metering of the lighting device may be accomplished by a
signal from the camera received by the microcontroller in the
lighting and effects device. Color/brightness balance can thus be
achieved.
[0022] Slave flashes will include self-contained electronic flash
units that respond to external triggers of some kind. Among the
sorts of triggers that would be suitable for use with the instant
invention are radio frequency (RF) signals, infrared (IR) signals,
and optical signals.
[0023] Optical slave flashes will be triggered by light. These
embodiments have sensors that detect a light pulse from another
flash device and then trigger immediately themselves. Since they
respond so quickly, the time delay between the trigger flash and
the slave flash does not affect the exposure of the photograph.
Optical flash units historically had a problem in large gatherings
where multiple flashes were present because an adjacent flash could
also trigger the slave flash units. Manufacturers have addressed
this problem by encoding the light bulbs so as to be immune from
secondhand flashes. Others have addressed the problem through the
use of IR or RF signals. The lighting and effects system of the
present invention is particularly suited for use with such optical,
IR or RF slave flash systems due to the lower power consumption and
longer duration of these triggers over prior art flash
technologies.
[0024] In various forms and embodiments, the lighting and effects
generator of the present disclosure may be adapted for being
mounted to a camera or a stand, and may include adapters for such a
purpose. The lighting apparatus may also be provided with a
diffusion lens or color gels, which may be integrated with or
detachable from the lighting and effects generator. The lighting
and effects generator may conveniently be provided in the form of a
kit, with one or more of a light panel, self-contained battery
unit, compact stand, connecting cable(s), adapter(s), lenses or
color gels, and so on, being provided in a single package to allow
flexibility and versatility to users in the field.
[0025] Further embodiments, variations and enhancements are also
disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 illustrates one environment in which the instant
invention might be utilized.
[0027] FIG. 2 is a block diagram of a lighting effects system
showing various components of a preferred system.
[0028] FIGS. 3A and 3B contain illustrations of different
approaches to mounting a preferred embodiment of the instant
invention on video and still cameras, respectively.
[0029] FIG. 4 is a diagram illustrating aspects of the lighting
effect provided by a lighting assembly such as, for example, shown
in FIG. 1.
[0030] FIGS. 5A and 5B are a block diagrams of two different types
of electronic controllers as may be employed, for example, in the
lighting effects system illustrated in FIG. 2.
[0031] FIG. 6 is a diagram that illustrates a preferred embodiment
of the lighting system and effects generator of the present
disclosure.
[0032] FIGS. 7A and 7B are diagrams of a lighting apparatus in
accordance with one embodiment as disclosed herein.
[0033] FIGS. 8A and 8B are diagrams of the lighting apparatus in
FIGS. 7A-B together with an attachable battery unit.
[0034] FIGS. 9A and 9B are diagrams showing attachment of the
lighting apparatus in FIGS. 7A-B and 8A-B to the attachable battery
unit of FIGS. 8A-B.
[0035] FIG. 10 is a diagram of one embodiment of a lighting effects
system having at least two different lamp colors.
[0036] FIG. 11 is a diagram of another embodiment of a lighting
effects system having at least two different lamp colors.
[0037] FIG. 12A is a diagram illustrating placement of a lens and
optional color gel on the integrated light panel and battery
apparatus of FIGS. 8A-B, and FIG. 12B is a side view diagram
illustrating the lens in place.
[0038] FIG. 13 is a diagram showing one possible means for mounting
an LED light panel to a camera.
[0039] FIG. 14 is a diagram illustrating attachment of mounting
pin(s) to the lighting apparatus shown in FIGS. 7A-B.
[0040] FIG. 15 is another view of a diagram illustrating attachment
of mounting pin(s) to the lighting apparatus shown in FIGS.
7A-B.
[0041] FIG. 16 is still another view of a diagram illustrating
attachment of mounting pin(s) to the lighting apparatus shown in
FIGS. 7A-B.
[0042] FIG. 17 is a diagram of a lighting array mounted atop a
circuit board.
[0043] FIG. 18 is a functional block diagram illustrating circuits
or components of an LED light panel in accordance with one
embodiment as disclosed herein.
[0044] FIGS. 19A and 19B contain preferred operating logic flow
charts that are suitable for use with the instant invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)
[0045] Before describing preferred embodiment(s) of the present
invention, an explanation is provided of several terms used
herein.
[0046] The term "lamp element" is intended to refer to any
controllable luminescent device, whether it be a light-emitting
diode ("LED"), light-emitting electrochemical cell ("LEC"), a
fluorescent lamp, an incandescent lamp, or any other type of
artificial light source. The term "semiconductor light element" or
"semiconductor light emitter" refers to any lamp element that is
manufactured in whole or part using semiconductor techniques, and
is intended to encompass at least light-emitting diodes (LEDs) and
light-emitting electrochemical cell (LECs).
[0047] The term "light-emitting diode" or "LED" refers to a
particular class of semiconductor devices that emit visible light
when electric current passes through them, and includes both
traditional low power versions (operating in, e.g., the 60 mW
range) as well as high output versions such as those operating in
the range of 1 Watt and up, though still typically lower in wattage
than an incandescent bulb used in such application. Many different
chemistries and techniques are used in the construction of LEDs.
Aluminum indium gallium phosphide and other similar materials have
been used, for example, to make warm colors such as red, orange,
and amber. A few other examples are: indium gallium nitride (InGaN)
for blue, InGaN with a phosphor coating for white, and Indium
gallium arsenide with Indium phosphide for certain infrared colors.
A relatively recent LED composition uses Indium gallium nitride
(InGaN) with a phosphor coating. It should be understood that the
foregoing LED material compositions are mentioned not by way of
limitation, but merely as examples.
[0048] The term "light-emitting electrochemical cell" or LEC"
refers to any of a class of light emitting optoelectronic devices
comprising a polymer blend embedded between two electrodes, at
least one of the two electrodes being transparent in nature. The
polymeric blend may be made from a luminescent polymer, a sale, and
an ion-conducting polymer, and various different colors are
available. Further background regarding LECs may be found, for
example, in the technical references D. H. Hwang et al, "New
Luminescent Polymers for LEDs and LECs," Macromolecular Symposia
125, 111 (1998), M. Gritsch et al, "Investigation of Local Ions
Distributions in Polymer Based Light Emitting Cells," Proc. Current
Developments of Microelectronics, Bad Hofgastein (March 1999), and
J. C. deMello et al, "The Electric Field Distribution in Polymer
LECs," Phys. Rev. Lett. 85 (2), 421 (2000), all of which are hereby
incorporated by reference as if set forth fully herein.
[0049] The term "color temperature" refers to the temperature at
which a blackbody would need to emit radiant energy in order to
produce a color that is generated by the radiant energy of a given
source, such as a lamp or other light source. A few color
temperatures are of particular note because they relate to the film
and photographic arts. A color temperature in the range of
3200.degree. Kelvin (or 3200.degree. K) is sometimes referred to as
"tungsten" or "tungsten balanced." A color temperature of
"tungsten" as used herein means a color temperature suitable for
use with tungsten film, and, depending upon the particulars of the
light source and the film in question, may generally cover the
color temperature range anywhere from about 1000.degree. Kelvin to
about 4200.degree. Kelvin. A color temperature in the range of
5500.degree. Kelvin (or 5500.degree. K) is sometimes referred to as
"daylight" or "daylight balanced." Because the color of daylight
changes with season, as well as changes in altitude and atmosphere,
among other things, the color temperature of "daylight" is a
relative description and varies depending upon the conditions. A
color temperature of "daylight" as used herein means a color
temperature suitable for use with daylight film, and, depending
upon the particulars of the light source and the film in question,
may generally cover the color temperature range anywhere from about
4200.degree. Kelvin to about 9500.degree. Kelvin.
[0050] Turning now to a first preferred embodiment, a lighting
effects system is provided herein that comprises an arrangement of
lamp elements on a panel or frame. The lamp elements may be
embodied as low power lights such as light-emitting diodes (LEDs)
or light emitting electrochemical cells (LECs), for example, and
may be arranged on the panel or frame in a pattern so as to provide
relatively even, dispersive light. The panel or frame may be
relatively lightweight, and may include one or more circuit boards
for direct mounting of the lamp elements. A power supply and
various control circuitry may be provided for controlling the
intensities of the various lamp elements, either collectively,
individually, or in designated groups, and, in some embodiments,
through pre-programmed patterns. Additionally, and according to the
instant invention, this lighting effects system is capable of
providing steading or continuous lighting and, upon demand,
strobing, pulsing, or otherwise increasing the output of the
lighting system relative to the continuous lighting level for use
in, for example, digital photography.
[0051] In another embodiment, a lighting effects system comprises
an arrangement of low power lights mounted on a frame having an
opening through which a camera can view a lighted subject, and one
or more mounting brackets for attaching the frame to a camera. The
low power lights may be embodied as LEDs or LECs, for example,
arranged on the frame in a pattern of concentric circles or other
uniform or non-uniform pattern. The low power lights may be
electronically controllable so as to provide differing intensity
levels, either collectively, individually, or in designated groups,
and, in some embodiments, may be controlled through pre-programmed
patterns. Again, and according to a preferred variation, this
lighting effects system will be capable of providing continuous and
pulsed lighting suitable for use in, for example, video and still
photography applications. Note that "continuous lighting" should be
broadly interpreted herein to include both lighting elements that
truly emit light continuously as well as light sources that might
appear to be continuous to the camera or the human eye even if they
are in reality generated by a series of closely spaced (in time)
light pulses (e.g., if the light is generated using pulse width
modulation).
[0052] FIG. 1 illustrates the general environment in which one
preferred embodiment of the instant invention might be used. In
some instances, a video camera 105 might be directed toward a
subject 110 that is being illuminated by inventive light 100. The
camera 105 of FIG. 1, while illustrated as a motion picture-type
camera, could be any type of image capture or optical viewing
device, whether analog or digital in nature. For example, the
camera 105 might use film, video tape, or solid-state image capture
circuitry (e.g., CCDs) and may be a still photography camera, a
motion picture camera, or some combination of the two.
[0053] As is illustrated in FIG. 1, according to this embodiment
the inventive light panel assembly 100 preferably utilizes a panel
light frame 120 which is attached to a stand 125. The panel light
frame 120 may include multiple panel light sections 123, 124, or
may be a single unitary panel light. The stand 125 may be of a
conventional nature, with a C-shaped yoke 130 for securing the
panel light frame 120 crossbar and allowing it to tilt for
directional lighting. A twisting handle 132 may be used to lock the
panel light frame 120 at a particular angle. The C-shaped yoke 130
may be rotatable or pivotable by placement atop a fluid head 134,
which, in turn, is positioned atop a stem 136 and tripod 138. The
panel lighting assembly 100 thus conveniently provides a variety of
directional lighting options for the panel light frame 120.
[0054] In alternative embodiments, a ball and socket mechanism may
be used to rotate or pivot an attached lighting panel, using socket
joints similar to those used, for example, for computer monitors.
Likewise, in any of the foregoing embodiments, motorization may be
employed to control the movement of the lighting yokes or stand.
Motorized controls are well known in the art for lighting apparatus
(particularly in the performing arts field) and the motorized
control may be either automated or manual in nature.
[0055] FIGS. 3A and 3B illustrate another preferred aspect of the
instant invention. In some arrangements, the lighting device might
be directly mounted on a camera as opposed to being stand-mounted.
In FIG. 3A, a preferred embodiment of the instant invention is
shown mounted on a conventional video camera and in FIG. 3B a
similar example of the instant invention is shown mounted on a
conventional SLR camera. As should be clear from these figures,
embodiment 300 is designed to be mounted on a video camera 305 or
digital still camera 310 and operate in conjunction therewith.
[0056] Although a panel-type configuration is preferred, other
configurations of the instant invention are certainly possible and
have been contemplated by the instant inventors (e.g., a
ring-shaped embodiment with light sources around its periphery).
That being said, FIG. 4 illustrates one reason why a panel-type
arrangement is preferred in many circumstances. FIG. 4 illustrates
the effect of the lighting frame assembly such as light frame 100
with light elements or lamps, collectively 320 generally arranged
as shown in FIGS. 3A and 3B. If a panel-type lamp configuration is
utilized, radiating light regions 420 and 421 from lamps arranged
on the front surface of the lighting frame 100 will overlap one
another in a manner so as to provide lighting from multiple angles.
With an arrayed pattern of lamp segments, the subject 410 may be
relatively evenly illuminated from every angle. The camera
(including any type of image capture device, whether film-based,
solid state/CCD, or otherwise) may be placed in any desired manner
with respect to a lighting frame 100.
[0057] Returning now to the general diagram of a lighting effects
system 201 illustrated in FIG. 2 (although the following comments
will apply to various other embodiments such as the lighting
assemblies shown in FIGS. 3A and 3B), the LEDs or other low power
lamps 205 may be operated at a standard direct current (DC) voltage
level, such as, e.g., 12 volts or 24 volts, and may be powered by a
power source 210 controlled by a power controller 212 such as is
generally shown in FIG. 2. The power source 210 can generally
comprise a standard electrical outlet (i.e., nominal 110 volt AC
power line), although in various embodiments the power source 210
could also be a battery having sufficient current to drive the LEDs
or other low power lamps 205. In some embodiments, the power
controller 212 may be omitted, and the lighting frame 202 may be
connected directly to the power source 210.
[0058] Block diagrams of two different types of power controllers
212 as may be used in various embodiments as described herein are
illustrated in FIGS. 5A and 5B, respectively. With reference to
FIG. 5A, a first type of power controller 512 has an input for
receiving an AC power source 503, and outputs a plurality of power
wires 547 preferably through a cable (e.g., cable 213 shown in FIG.
2) for connection to the lighting frame 202. The power controller
512 may further comprise a power converter 520, the nature of which
depends upon the type of power source 210. If the power source is
an AC source, the power converter 520 may comprise an AC-to-DC
converter and appropriate step-down power conversion circuitry
(e.g., a step-down transformer). On the other hand, if the power
source is a DC source (e.g., a battery), the power converter 520
may comprise a DC-to-DC converter, if necessary. The design and
construction of power converters is well known in the field of
electrical engineering, and therefore is not be described herein in
detail.
[0059] The power converter 520 is preferably connected to a
plurality of switches 522, which may be solid state devices (e.g.,
transistors) or analog devices (e.g., relays), each switch
controlling power delivered by the power converter 520 to one of
the wires 547 output by the power controller 512. A switch selector
542 controls the on/off state each switch (or group) in the set of
switches 522. A manual interface 530 is provided to allow operation
of the switches 522 according to manual selection. The manual
interface 530 may include a master power switch 531, switch
controls 532, and, optionally, an effects selector 533. The switch
controls 532 may include an individual manual switch, button or
other selection means for each individual switch provided in the
set of switches 522, or else may comprise a control mechanism (such
as knob or reduced number of manual switches, buttons or other
selection means) for selecting groups of switches 522 according to
predesignated arrangements. As but one example, assuming a light
arrangement such as shown in FIG. 3B (taken in combination with
FIG. 5A), a knob provided as part of the switch controls 532 could
have a first setting to select all of the light segments 325, 330,
335, 340, 345, 350, 355, 360 thereby illuminating all 320 light
elements, a second setting to select every other light segments
325, 335, 345 and 355, and a third setting to select every fourth
of light segment 325, 340, 360, thus providing options of 100%, 50%
and 25% total light output. The switch selector 542 would then
convert each knob setting to a set of control signals to the
appropriate switches 522, which in turn would control power to the
wires 547 supplying power to the light segments.
[0060] As another example, the switch controls 532 could include an
individual manual switch, button or other selection means for each
light segment 325, 330, 335, 340, 345, 350, 355 and 360 or group of
light segments in the lighting arrangement.
[0061] An effects generator 543 (FIG. 5A) may optionally be
included in the power controller 512, along with an effects
selector 533 which forms part of the manual interface 530. The
effects generator 543 may provide the ability to create various
lighting effects, such as, e.g., dimming, strobing, pulsation, or
pattern generation. The effects selector 543 may affect all of the
switches 522 simultaneously, or else may affect individual switches
or groups of switches 522, depending upon the desired complexity of
the lighting effects. Dimming may be accomplished, for example,
through a manual control knob or multi-position switch on the
effects selector 533. The dimming control may be electronically
implemented, for example, in an analog fashion through a variable
resistive element, or in a digital fashion by detecting the
selected manual setting and converting it to selecting power
setting through, e.g., selected resistive elements in a resistive
ladder circuit or through a variable duty cycle delivered to the
lights. Where the switches 522 are implemented, for example, as
controllable variable amplifiers, the selectable resistance may be
used to control the output of each amplifier and thereby the light
output by the amplifier's respective light segment 325-360 (or
group of light segments FIG. 3B). In other embodiments, the dimming
control may optionally be applied to the output of switches 522.
Where dimming control is applied collectively, it may be
implemented by applying the selected dimming control level to the
incoming signal from the power converter 520, which is supplied to
all of the switches 522 collectively. Other variations for
implementing dimming control are also possible and will be apparent
to those skilled in the art of electrical engineering.
[0062] Strobing may be accomplished by generating an oscillating
signal and applying it as a control signal either upstream or
downstream from the switch selector 542. The frequency of
oscillation may be selectable via a manual knob, switch or other
selection means as part of the effects selector 533.
[0063] Pattern generation may be accomplished by, e.g., manual
selection from a number of predefined patterns, or else through an
interface allowing different pattern sequencing. Patterns may
include, for example, strobing or flashing different groups of
light segments 325, 330, 335, 340, 345, 350, 355, and 360 (given
the example of FIG. 3B) in a predefined sequence (which may be a
pseudo-random sequence, if desired), strobing or flashing different
light elements 320 of the light segments 325-360 in a predefined
(or pseudo-random) sequence, gradually dimming or brightening light
segments 325-360 (individually, in groups, or collectively), or
various combinations of these effects.
[0064] Alternatively, rather than providing a separate effects
selector 533, certain effects may be combined with the switch
controls 532. For example, a dimmer switch (knob) 380 could be used
to both activate a particular light segment (such as 340), or group
of light segments (such as 325, 340, and 360) and also control
light output via rotation of the dimmer switch (knob) 380.
[0065] FIG. 5B is a block diagram showing another example of a
power controller 552 as may be used, for example, in the lighting
effects system 200 of FIG. 2 or other embodiments described herein.
Like the power controller 512 shown in FIG. 5A, the power
controller 552 shown in FIG. 5B includes a power source input 553
connected to a power converter 560. It further includes a set of
switches 562 receiving power from the power converter 560, and
providing power to individual wires 597 which are conveyed,
preferably by cable, to the lighting frame assembly 201 of the
lighting effects system 200. The power controller 552 also includes
a switch selector 572, which may comprise, for example, a set of
registers which provide digital signals to the switches 562 to
control their on/off state.
[0066] The power controller 552 includes a processor 574 which may
be programmed to provide various lighting effects by manipulating
the switch selector 572 (for example, by changing values in
registers which control the on/off states of the switches 562). The
processor 574 may interface with a memory 575, which may comprise a
volatile or random-access memory (RAM) portion and a non-volatile
portion (which may comprise, e.g., ROM, PROM, EPROM, EEPROM, and/or
flash-programmable ROM), the latter of which may contain
programming instructions for causing the processor 574 to execute
various functions. The memory 575 may be loaded through an I/O port
576, which may include an electrical serial or parallel interface,
and/or an infrared (IR) reader and/or bar code scanner for
obtaining digital information according to techniques well known in
the field of electrical engineering and/or electro-optics. An
interface 580 may also be provided for programming or otherwise
interfacing with the processor 574, or manually selecting various
lighting effects options through selectable knobs, switches or
other selection means, as generally explained previously with
respect to FIG. 5A. The processor-based control system illustrated
in FIG. 5B may also include other features and components which are
generally present in a computer system.
[0067] In operation, the processor 574 reads instructions from the
memory 575 and executes them in a conventional manner. The
instructions will generally cause the processor 574 to control the
switch selector by, e.g., setting various digital values in
registers whose outputs control the switches 562. The programming
instructions may also provide for various lighting effects, such as
dimming, strobing, pulsation, or pattern generation, for example.
To accomplish dimming, the processor 574 may be programmed select
binary-encoded values to load into registers of the switch selector
572, which in turn select a variable resistance value which
controls the output from each individual or group of switches 562.
To accomplish strobing, the processor 574 may be programmed to turn
the switches 562 on and off according to a predesignated pattern
dictated by the programming instructions. The processor 574 may
make use of one or more electronic timers to provide timing between
on and off events. The programming instructions may provide that
the switches 562 are turned on and off according to designated
sequences, thus allowing the capability of pattern generation via
the processor 574. As mentioned before, patterns may include, for
example, strobing or flashing all or different groups of light
segments 325-360 (given the example of FIG. 3) in a predefined (or
pseudo-random) sequence, strobing or flashing different low power
lamps 320 of the light segments 325-360 in a predefined (or
pseudo-random) sequence, gradually dimming or brightening the light
segments 325-360 (individually, in groups, or collectively), or
various combinations of these effects is contemplated. Predefined
(or pseudo-random) sequence, gradually dimming or brightening the
lamps 320 (individually, in groups, or collectively), or various
combinations of these effects is contemplated.
[0068] Turning next to FIG. 6 which illustrates a preferred
embodiment of the instant lighting and effects system, continuous
regulator 610 receives power from either battery 612, or optionally
through external power connector 614. Preferably diodes 616 and 618
essentially "or" the power from either source 612 or 614 such that
the source with the highest voltage will provide the power to
regulator 610. Diodes 616 and 618 further preferably provide
reverse voltage protection such that an inadvertent insertion of
battery 612 or application of reversed voltage at connector 614
will not damage regulator 610.
[0069] In a preferred arrangement, regulator 610 selectively
regulates the current through LED array by measuring the voltage
across current sense resistor 622. Potentiometer 624 provides a
selectable reference to regulator 610 to set the level at which the
LED current will be regulated.
[0070] Preferably regulator 610 is a switch mode regulator which
will provide true direct current to LED array 620. One such device
suitable for the present invention is Model TPS 61165 manufactured
by Texas Instruments of Dallas, Tex. However, a linear regulator
would also work satisfactorily, albeit perhaps at a somewhat lower
efficiency. Alternatively, regulator 610 could employ pulse width
modulation to accomplish dimming.
[0071] To obtain a flash of light from LED array 620, in the
preferred embodiment a burst control circuit 630 is provided.
Typically, circuit 630 will maintain a reservoir of electrical
energy at a voltage somewhat higher than the output 626 of
regulator 610 when a sync pulse, or switch closure, is provided at
sync input 632. When burst circuit 630 detects a sync pulse, the
stored energy is provided at output 634, preferably for a
predetermined period of time causing LED array 620 to produce a
flash of light. In one preferred embodiment, the energy stored by
circuit 630 is a known quantity which will drive LED array 620 in a
known manner, by way of example and not limitation, perhaps at
eight times its maximum continuous current. Alternatively, burst
control circuit may use feedback from current sense resistor 622 to
control the current during the flash duration.
[0072] In a preferred embodiment, diode 628 prevents the burst
output 634 from adversely affecting regulator 610 and diode 636
prevents the output of regulator 610 from adversely affecting
circuit 630.
[0073] FIGS. 3, 4, 7A and 7B are diagrams of a lighting apparatus
700 in accordance with one or more embodiments as disclosed herein.
The lighting apparatus 700 is preferably portable and versatile in
nature, as further described herein. The lighting apparatus 700 in
this example includes a panel, fixture or frame (hereinafter
"panel") 702 having a plurality of semiconductor light elements
(such as LEDs or LECs) 4705 mounted on a mounting surface 704 of
the panel 702. Note that for purposes of the instant disclosure, a
surface mount semiconductor light element is any LED (semiconductor
light element) that does not have leads for through hole mounting.
Persons of ordinary skill in the art will readily understand the
meaning of "through hole" as that term is used in the semiconductor
industry.
[0074] As illustrated in FIG. 7A, the semiconductor light elements
705 may be disposed in uniform arrays to provide a broad light
source. The mounting surface 704 may include one or more circuit
board assemblies, generally constructed in accordance with the
principles described with respect to FIG. 17. Although the
semiconductor light elements 705 are illustrated as being arranged
in uniform arrays, they may be arranged in other patterns as well.
Furthermore, while the panel 702 is shown as being generally
rectangular in shape, the panel 702 may alternatively be of any
suitable shape, including, for example, hexagonal, octagonal, or
other polygonal or semi-polygonal, or round, oval, square, or
ring-shaped.
[0075] The semiconductor light elements 705 may be surface mounted
or through hole. The light elements or LEDs may have screw-in bases
or other similar physical attachment means, such that the LEDs can
be easily removed and replaced.
[0076] The panel 702 may further include an integrated dimmer
control 726, in the form of a knob, switch, or other mechanism, to
allow the intensity of the semiconductor light elements 705 to be
adjusted. As one example of an implementation, a dimmer control 726
(e.g., in the form of a manual knob) may control the conductance of
a potentiometer or variable resistor, to adjust the amount of
current reaching the semiconductor light elements 705. More than
one dimmer control 726, and/or switches, may optionally be
provided, so as to control groups of semiconductor light elements
705, for example, or to turn on or off certain groups of the
semiconductor light elements 705. An example of electronic
circuitry as may be used in connection with dimmer control 726 is
described with respect to FIG. 18.
[0077] As illustrated in FIG. 7B, the panel 702 may include a
socket 724 or other input for receiving a power connection (e.g.,
cable) to provide electrical power to the semiconductor light
elements 705. The panel 702 may also include various heat
dissipating fins 712, which may be arranged, for example, in arrays
of metal or heat conductive rods, integrated on the back side of
the panel 702, in order to efficiently dissipate heat generated by
the semiconductor light elements 705. The heat dissipating fins 712
may generally be similar to those described elsewhere herein, for
example, with respect to FIG. 8A. The heat dissipating fins 712 may
be of any suitable size or shape, and may be extended, for example,
to accommodate higher wattage LEDs or light elements. Other types
of heat dissipation mechanisms may also be used.
[0078] The lighting apparatus 700 of FIGS. 8 and 9 may be
particularly adapted to receive an attachable/detachable battery
unit, so as to provide a power source. FIGS. 8A and 8B are diagrams
of a panel-based lighting apparatus 802 such as illustrated in
FIGS. 7A-B, together with an attachable battery unit 830, to form a
self-contained, self-powered lighting apparatus 800. The battery
unit 830 may be attachable to the panel 802 in any of a variety of
manners. In the particular example shown in FIGS. 8A and 8B, the
battery unit 830 comprises a set of struts 832 that attach to
corresponding receptacles 836 of the panel 802. FIG. 8A shows a
perspective view of the light panel 802 and battery unit 830
slightly separated, while FIG. 8B shows a side view of them
attached to one another, with the struts 832 inserted in the
receptacles 4836 of the panel 4802. FIGS. 9A and 9B are diagrams
showing attachment of the light panel 4802 to the attachable
battery unit 830. FIG. 9A in particular is a simplified diagram
omitting certain details such as the heat dissipating fins.
[0079] A wide variety of alternative means may be used to attach
the battery unit 830 to the panel 802; by way merely of example,
the battery unit 830 may slidably attach and engage with the panel
802, or may have external tabs that grip the panel 802, or may have
pins or screws that engage with the panel 802.
[0080] The battery unit 830 preferably delivers power to the light
panel 802 through an electrical connector 840, which may take the
form of, e.g., a jumper cord, and may insert into electrical
sockets 834 (in the battery unit 830) and 824 (in the panel 802).
Alternatively, the front side of the battery unit 830 and backside
of the panel 802 may be provided with a mating male/female
electrical plug and socket, which automatically engage when the
battery unit 830 is attached to the panel 802. As with the lighting
apparatus 700 of FIGS. 7A-B, a dimmer switch 826 may be provided in
a convenient location on the panel 802, to adjust the light
intensity. One or more batteries, possibly replaceable, may be
integrated with battery unit 830. The battery, or batteries, may
have a nominal voltage rating of appropriate level, such as 12
volts. The battery, or batteries, of battery unit 730 is/are
preferably rechargeable in nature.
[0081] Each of the lamp segments 325-360 preferably comprises a
plurality of low power lamp elements 320, such as illustrated, for
example, in FIG. 3B. The low power lamps are preferably solid state
in nature and may comprise, for example, light-emitting diodes
(LEDs), light-emitting crystals (LECs), or other low power,
versatile light sources. Slight color variations may be added
relatively easily to the lenses of LEDs to compensate for color
deficiencies without significantly impacting the overall light
output. Colored LED lenses may also be used to generate a desired
color (such as red, green, etc.), but, since colored lenses are
subtractive in nature, the stronger the color, generally the more
the output of the LED will be dimmed. White LEDs typically utilize
clear or nearly clear lenses; however, in any of the embodiments
described herein, a clear LED lens may be manufactured with slight
subtractive characteristics in order to minimize any color spikes
and/or non-linearities in the output of an LED.
[0082] The lighting apparatuses of FIGS. 10 and 11 may, if desired,
be physically embodied in a manner as described elsewhere herein.
For example, the lighting apparatus may be embodied in a portable
frame such as that generally illustrated in and/or described with
respect to FIGS. 3, 7, 8, etc. The principles and underlying
concepts associated with the embodiments of FIGS. 10 and 11 may be
extended to support more than two colors of lamp elements 320 or
705. Moreover, the lighting apparatuses of FIGS. 10 and 11 may
utilize any number of lamp elements in a bi-color or other
multi-color arrangement in pattern.
[0083] Various embodiments of lighting apparatus as described
herein utilize different color lamp elements in order to achieve,
for example, increased versatility or other benefits in a single
lighting mechanism. Among the various embodiments described herein
are lamp apparatuses utilizing both daylight and tungsten lamp
elements for providing illumination in a controllable ratio. Such
apparatuses may find particular advantage in film-related
applications where it can be important to match the color of
lighting with a selected film type, such as daylight or
tungsten.
[0084] Alternatively, or in addition, lamp elements of other
colorations may be utilized. It is known, for example, to use
colored lamp elements such as red, green, and blue LEDs on a single
lighting fixture. Selective combinations of red, green, and blue
("RGB") lamp elements can generally be used to generate virtually
any desired color, at least in theory. Lighting systems that rely
upon RGB lamp elements can potentially used as primary illumination
devices for an image capture system, but suffer from drawbacks. One
such problem is that the red, green, and blue colors generated by
the light elements do not necessary mix completely. The discrete
RGB lamp elements (e.g., LEDs) each project a localized "pool" of
its individual primary color. This manifests as spots of color, or
bands of individual or partially mixed colors. One of the presently
available solutions to correct for this problem is mixing the
colors using a diffusion technique. Diffusion mixing can be
accomplished by adding defractors, gratings, or white
opal-appearing filters, for example. Unfortunately, these
techniques end up reducing the overall output of the lighting
apparatus and, more importantly, severely reduce the ability of the
LEDs to "project" light in a direct fashion. Another problem for
illumination systems which rely upon RGB color mixing is that not
all of the LEDs are generally used at full power for most lighting
situations. One or two of the LED color groups typically have to be
dimmed in order for the desired color to be generated, which can
further reduce the overall light output. When these factors are
considered in combination, RGB based lighting apparatus may not be
well suited for providing primary illumination for image capture
applications (such as film).
[0085] While the foregoing discussion has principally focused on
RGB based lighting apparatus, similar problems and drawbacks may be
experienced when employing lamp elements in other color
combinations as well.
[0086] In various embodiments as disclosed herein, a lighting
apparatus is provided which utilizes two or more complementary
colored lamp elements in order to achieve a variety of lighting
combinations which, for example, may be particularly useful for
providing illumination for film or other image capture
applications. A particular example will be described with respect
to a lighting apparatus using lamp elements of two different
colors, herein referred to as a "bi-color" lighting apparatus. In a
preferred embodiment, the bi-color lighting apparatus utilizes
light elements of two different colors which (unlike red, green,
and blue) are separated by a relatively small difference in their
shift or color balance. When reference is made herein to light
elements of two different colors, the light elements may, for
example, include a first group which provide light output at a
first color and a second group which provide light output at a
second color, or else the light elements may all output light of a
single color but selected ones of the light elements may be
provided with colored LED lenses or filtering to generate the
second color. In a preferred embodiment, as will be described, the
bi-color lighting apparatus uses lamp elements having daylight and
tungsten hues (for example, 5200.degree. K and 3200.degree. K color
temperatures, respectively). Other bi-color combinations may also
be used and, preferably, other combinations of colors which are
closely in hue or otherwise complementary in nature.
[0087] One possible advantage of a bi-color lighting system as will
be described in certain embodiments below is the ability to more
easily blend two similar colors (e.g., 5500 K and 3200 K color
temperature hues), particularly when compared to a tri-color (e.g.,
RGB) lighting system that relies upon opposing or widely disparate
colors. The blending process of two similar colors is not nearly as
apparent to the eye, and more importantly in certain applications,
is a more suitable lighting process for film or video image capture
devices. In contrast, attempting to blend 3 primary or highly
saturated (and nearly opposite colors) is much more apparent to the
eye. In nature one may visually perceive the blending of bi-colors,
for example, from an open sky blue in the shade, to the warmth of
the direct light at sunset. Such colors are generally similar, yet
not the same. Their proportion in relation to each other is a
naturally occurring gradient in most every naturally lit situation.
This difference is the basis of most photographic and motion
picture lighting hues. These hues give viewers clues as to time of
day, location and season. Allowing separate control of the two
different color lamp elements (such as LEDs), through two separate
circuit/dimmer controls or otherwise, provides the ability to
easily adjust (e.g., cross-fade, cross-dim, etc.) between the two
colors because they do not have significant color shifts when
dimmed and blend in a visually pleasing manner, allowing the type
of color gradients that occur in nature. In addition, virtually all
still and motion picture film presently used in the industry is
either tungsten or daylight balanced, such that various
combinations of daylight and tungsten (including all one color) are
well matched directly to the most commonly used film stocks. These
features make various of the lighting apparatus described herein
particularly well suited for wide area still, video, and motion
picture usage, especially as compared to RGB-based or other similar
lighting apparatus. The above principles may also be extended to
lighting systems using three or more lamp element colors.
[0088] FIG. 10 is a block diagram of one embodiment of a lighting
effects system 1000 having at least two different lamp element
colors. As illustrated in FIG. 10, the lighting effects system 1000
comprises a lighting frame mounting surface 1002 having a plurality
of lamp elements 1005 which, in this example, include daylight LEDs
1004 and tungsten LEDs 1003, although different lamp elements
and/or different colors could be chosen. The lighting effects
system 1000 further comprises various control electronics for
controlling the illumination provided by the lamp elements 1005. In
particular, the lighting effects system 1000 comprises an intensity
control adjustment 1042, an intensity control circuit 1045, a ratio
control adjustment 1041, and a ratio control circuit 1046. The
intensity control adjustment 1042 and ratio control adjustment 1041
may each be embodied as, e.g., manual control knobs, dials,
switches, or other such means, or alternatively may be embodied as
a digital keypad, a set of digital buttons, or the like. A visual
display (not shown) such as an LCD display may be provided to allow
the operator to view the settings of the intensity control
adjustment 1042 and ratio control adjustment 1041. Alternatively,
the ratio control adjustment 1041 and/or intensity control
adjustment 1042 may comprise digital commands or values received
from a computer or similar device.
[0089] In operation, setting the intensity control adjustment 1042
selects the illumination level for the lamp elements 1005, while
setting the ratio control adjustment 1041 selects the relative
intensities between, in this example, the daylight LEDs 1004 and
the tungsten LEDs 1003. The intensity control circuit 1052 and
ratio control circuit 1046 may comprise analog and/or digital
circuitry, and the output of the ratio control circuit 1046
modifies the incoming power supply separately for the daylight LEDs
1004 and the tungsten LEDs 1003 in a manner dictated by the setting
of the ratio control adjustment 1041. Accordingly, by use of the
ratio control adjustment 1041, the operator may select more
daylight illumination by increasing the relative intensity of the
daylight LEDs 1004 or may select more tungsten illumination by
increasing the relative intensity of the tungsten LEDs 1003. To
increase or decrease the overall light output intensity, the
operator may adjust the intensity control adjustment 1042. The
lighting effects system 1000 thereby may provide different
combinations of daylight/tungsten coloration to match a wide
variety of settings and circumstances, with the two colors being
generally complementary in nature and thus providing a balanced,
well blended illumination effect.
[0090] FIG. 11 is a diagram of another embodiment of a lighting
effects system having at least two different lamp colors. As
illustrated in FIG. 11, and similar to FIG. 10, the lighting
effects system 1100 comprises a lighting frame mounting surface
1102 having a plurality of lamp elements 1105 which, in this
example, include daylight LEDs 1104 and tungsten LEDs 1103,
although different lamp elements and/or different colors could be
chosen. The lighting effects system 1100, as with that of FIG. 10,
further comprises various control electronics for controlling the
illumination provided by the lamp elements 1105. In particular, the
lighting effects system 1100 comprises individual intensity control
adjustments 1151, 1152 for daylight and tungsten lamp elements
(e.g., (LEDs) 1103, 1104, and individual intensity control circuits
1156, 1157 also for the daylight and tungsten LEDs 1103, 1104. The
tungsten intensity control adjustment 1151 and daylight intensity
control adjustment 1152 may, similar to FIG. 10, each be embodied
as, e.g., manual control knobs, dials, switches, or other such
means, or alternatively may be embodied as a digital keypad, a set
of digital buttons, or the like. A visual display (not shown) such
as an LCD display may be provided to allow the operator to view the
settings of the two intensity control adjustments 1151, 1152.
Alternatively, the intensity control adjustments 1151, 1152 may
comprise digital commands or values received from a computer or
similar device.
[0091] In operation, setting the tungsten intensity control
adjustment 1151 selects the illumination level for the tungsten
LEDs 1103 via the tungsten intensity control circuit 1156, and
setting the daylight intensity control adjustment 1152 selects the
illumination level for the daylight LEDs 3404 via the daylight
intensity control circuit 1157. The relative settings of the
tungsten intensity control adjustment 1151 and the daylight
intensity control adjustment 1152 generally determine the relative
intensities between, in this example, the daylight LEDs 1104 and
the tungsten LEDs 1103. The intensity control circuits 1156, 1157
may comprise analog and/or digital circuitry, and the relative
outputs of the tungsten intensity control circuit 1156 and the
daylight intensity control circuit 1156 generally determine the
illumination level and composition. The operator may select more
daylight illumination by increasing the relative intensity of the
daylight LEDs 1104 or may select more tungsten illumination by
increasing the relative intensity of the tungsten LEDs 1103. The
lighting effects system 1100 thereby may provide different
combinations of daylight/tungsten coloration to match a wide
variety of settings and circumstances, as with the FIG. 10
embodiment.
[0092] Because the two different colors of LEDs (e.g., daylight and
tungsten) can be controlled separately (through common or separate
circuitry), and because these particular LEDs, or other similar
complementary colors, do not have significant color shifts when
dimmed, it would be relatively straightforward to adjust (e.g.,
cross-fade, cross-dim) between the two colors and, for example,
provide a variety of natural light illumination effects for various
types of common film stock.
[0093] According to one or more embodiments as disclosed herein, a
versatile lighting apparatus in the form of an LED-based light
panel is provided, preferably having a variety of mounting options
or configurations, an attachable or integrated battery unit, and
alternative means for receiving a power supply input. In a
preferred embodiment, the versatile LED-based light panel includes
a panel frame, and a plurality of LEDs or other light elements
secured to the panel frame. A self-contained battery unit securably
attaches to the outside of the panel frame. The light panel may
have a dimmer switch, and may also be capable of receiving power
from a source other than the self-contained battery unit. The
lighting apparatus can be mounted to a camera or a stand through
adapters. Diffusion lenses or color gels can be integrated with or
detachable from the light panel. The lighting apparatus may
conveniently be provided in the form of a kit, with one or more of
a light panel, self-contained battery unit, compact stand,
connecting cable(s), adapter(s), lenses or color gels, and so on,
provided in a single package.
[0094] It is contemplated that the lighting and effects generator
of the present disclosure could, due to its size and weight, be
transported quickly and easily by a photographer to a location and
rapidly setup to produce a lighting and effects system which
provides continuous source of illumination for modeling and video
capture as well as pulse, flash or strobe boost illumination for
still photography. Such a system capable of being battery powered
would not require cabling and thus could be used in crowded areas
without a concern of someone tripping over cables. A portable and
therefor spontaneous battery powered, cordless, LED studio can be
set up at any desired location.
[0095] A diffusion lens or filter may also be used, by itself or in
conjunction with a color gel or colored lens, to diffuse or soften
the outgoing light. A diffusion lens or filter may be formed of,
e.g., clear or white opaque plastic, and may be configured in a
shape of similar dimension to the panel 702 or 802 to facilitate
mounting thereon. One such diffusion filter 1229 is shown in FIG.
12A. A preferred diffusion filter/lens would be a Light Shaping
Diffusor material (e.g., holographic, etc.). A color correction
mechanism, such as a lens filter and/or color gel, may be used to
alter the color of the light elements of a lighting apparatus such
as depicted in FIGS. 7A-B or 8A-B. For example, LED light sources
could, if necessary, be converted to "tungsten daylight" (similar
in hue to an incandescent bulb) by use of a color gel and/or
colored lens.
[0096] The lighting apparatuses 700 and 800 are preferably adapted
to be utilized in conjunction with various lenses and/or color
gels, to increase their versatility. FIG. 12A is a diagram
illustrating one embodiment having a lens 1210 and optional color
gel 1229 used with the lighting apparatus 800 illustrated in FIGS.
8A-B, and FIG. 12B is a side view diagram illustrating the lens
1220 in place. The lens 1210 is preferably readily attachable to
the panel 802 of the lighting apparatus 800, by fastening means
such as complementary Velcro patches 1222, 1212. Alternatively, the
lens 1210 could snap or slide on to the panel 802, or be attached
using screws, nuts/bolts, pins, or other such means. The
filter/lens 1210 (as with 6327, described later herein) may
comprise, e.g., a Fresnel lens, a holographic lens, or any other
type of lens, or combinations thereof. The color gel 1229 is
preferably inserted beneath the lens 1210 and is secured beneath
it. As depicted in FIG. 12A, the color gel 1229 has cutouts on each
of the corners so as not to interfere with the Velcro patches 1222,
1212.
[0097] The lighting apparatus 700 is preferably portable in nature
and can be adapted for use in a variety of ways. To facilitate
mounting of the lighting apparatus 700 (whether or not attached to
a battery unit, as depicted in FIGS. 8A-B), the lighting apparatus
700 may be provided with one or more adapters. FIG. 59 is a diagram
illustrating an example of a lighting apparatus 700 in the form of
a panel 702 with one or more adapters 5906, 5907 for mounting or
affixing the panel 702 to a camera, stand, or other object or
surface. In the example depicted in FIG. 59, the adapters 5906,
5907 are in the form of receptacles suitable for receiving a
mechanical pin (or a similar fastener such as a screw or bolt),
allowing convenient and rapid deployment of the lighting apparatus
700 on, e.g., a camera or stand. Other adapters or fastening means
(e.g., hinged tabs, sliding/coupling members, etc.) may also be
used.
[0098] Examples of ways in which the light apparatus 700 can be
mounted on a camera, stand or other object or surface are
illustrated in at least FIGS. 1, 3, 4, etc. For example, the
lighting apparatus 700 may be mounted to a camera, directly to the
camera housing or to an arm attached to the camera housing. FIG. 1A
is a diagram showing one possible mechanism for mounting a lighting
apparatus 700 in the form of a light panel to a camera 1307. While
the description below is explained in terms of lighting apparatus
700, it also applies to the lighting apparatus 800 having an
attachable battery unit, as well as other possible lighting
apparatuses as well. In FIG. 13, the camera 1307 includes or is
configured with an attachment arm 1310 which may be used for
mounting the lighting apparatus 700.
[0099] FIGS. 14 through 16 are diagrams illustrating other
attachment options, using various mounting pins, in connection with
the lighting apparatus 700 of FIGS. 7A-B. FIG. 14, for example,
illustrates a mounting pin 1410 that may be used to allow the
lighting apparatus 700 to attach to a stand or tripod.
[0100] FIG. 16 illustrates attachment of the lighting apparatus 700
to a mounting pin 1410 similar to that shown in FIG. 14, but in
this instance being coupled to an adapter on the narrow side of the
lighting apparatus 700 instead of its long side.
[0101] In FIG. 15, the lighting apparatus 700 is attached to a
stand or camera using a mounting pin 1450. The mounting pin 1450 in
this example also includes a threaded pin 1469 and a cylindrical
body 1462. In this case, the mounting pin 1450 may have a T-bar
1459 that is securably attached to the cylindrical body 1462, or
else fits into a hollow receptacle to secure it to the cylindrical
body 1462 of the mounting pin 1450, thereby allowing it to slide
onto a camera having curved fins or other members for receiving the
wings of the T-bar 1459. The mounting pin 1450 may alternatively
have a pin, receptacle, or other member for mounting into a camera
shoe or a stand, thus securing the lighting apparatus 700 to the
camera or stand.
[0102] Various options and accessories as may be used in connection
with the lighting assembly frame. The lighting frame may be
augmented with a diffusion filter and/or a color filter which may,
if desired, be secured into place through a cover (e.g., a clear
plastic cover) which locks or snaps onto the lighting frame.
Similar accessories may be utilized, for example, in connection
with the lighting frame 302 illustrated in FIGS. 3 and 4.
Illustrations of filtering techniques, through the use of
waveguides and other means, are described, for example, in U.S.
Pat. Nos. 6,272,269 and 6,270,244, both of which are incorporated
by reference herein in their entirety.
[0103] It will be appreciated that, in various embodiments, a
flexible, lightweight and functional lighting effects system is
provided, whereby relatively uniform light may be used in
illumination of a subject or area. The lighting effects system may,
in various embodiments, allow a lighting frame to be secured to a
camera or other image capture device, so as to permit the lighting
system to be mobile and move in tandem with the camera or other
image capture device, if desired. Also, in various embodiments, the
lighting effects system may provide a variety of lighting patterns,
including programmable patterns by which individual or groups of
lights can be controlled for different lighting effects. The
lighting frame may, in certain instances, be formed in multiple
sections and hinged to allow the lighting frame to fold, or else
snapped apart section by section, for ease of transport.
[0104] The light and effects generator of the present disclosure
may be adapted for implementation into a soft box. This would allow
for the projection of a soft light deep into a subject. The
advantages of such a soft light embodiment include all of the known
advantages of a soft box such as the use of diffusion and control
of the light with little light loss.
[0105] The particular advantages of the light and effects generator
of the present disclosure implemented in a soft box include the
fact that the LED light array generates less heat than conventional
systems and particularly the fact that it provides a large light
source with a flash with minimal feature depth. This is
particularly significant for overhead lighting applications or
anywhere where space is a factor in light placement.
[0106] In addition, a light of the present disclosure in a soft box
could also include lensing and/or multi lensing. Contiguous lensing
could be provided to create a seamless light source over the entire
face of the light. Such light could then be projected deep into a
subject for photography.
[0107] Another aspect of the light and effects generator of the
present disclosure is that when coupled with a camera, it is
possible to use the camera as a light meter without the requirement
of an additional light meter. In this way, a color chart, well
known in photography is used in view of the camera. A test shot is
then performed using the color chart. The lighting information
matching the color chart is then transferred directly to the light
of the present disclosure to balance the color. This information is
transferred in a communication either wired or wireless
communication between the camera and the microcontroller in the
light. In this way color brightness control may be achieved as well
as the depth of the lighting and changes of color in relation to
depth.
[0108] In various alternative embodiments, the lighting frame need
not be shaped as shown in FIGS. 1, 3, 4, etc. For example, the
lighting frame may be round, square, hexagonal, octagonal, or other
polygonal, or could, for instance, have a partially polygonal
shape. Preferably, the lighting frame is relatively thin, as
compared to its overall size, although it need not be. Also, the
lighting frame preferably has a hole generally centered therein to
allow a camera or other image capture device to view through the
frame, although in some embodiments a viewing hole may not be
present. The exterior portion of the lighting frame, or at least
the exterior portion thereof, is preferably made of a lightweight,
durable material such as plastic and/or lightweight metal (e.g.,
aluminum), optionally anodized, although in various embodiments it
can be made of other materials as well, including any type of
metal, wood, plastic, or combination thereof. The interior lighting
frame portion may advantageously comprise a printed circuit
board.
[0109] Other variations may pertain to the manner of attaching the
lighting frame to a camera or other image capture device. Rather
than using a single mounting bracket or assembly, for example,
multiple mounting brackets or assemblies may be used. Also, the
mounting bracket or assembly may be permanently attached or affixed
to the lighting frame, and may be, for example, retractable or
foldable for convenience of transportation. The lighting frame may
attach either to the camera body or to the lens portion of the
camera. The lighting frame may attach to the camera lens through
any of a variety of means, such as by engaging an outer camera lens
threading through a threading on the interior circular hole of the
lighting frame, engaging an inner camera lens threading by
providing a complementary threaded extension for that purpose, by a
strap means to secure the lighting frame to the camera and/or
stand, or by a "hose-clamp" type strap which grips the outer
cylinder of the camera lens. Also, rather than attaching to the
camera, the lighting frame may be portable, and may be outfitted
with handles for lighting crew to manually carry or hold the
lighting frame, or may be adapted to attach to a stand or fixture
for providing stationary illumination. The lighting frame may also
be adapted to attach to a machine arm or other contrivance for
allowing the lighting effects system to be moved as needed for
filming or other desired purposes.
[0110] Further embodiments, variations, and modifications pertain
to the type of lamp elements that may be utilized in a lighting
effects system and/or the manner of constructing a lighting frame
particularly well suited for placing numerous lamp elements
thereon. One method of construction involves the use of surface
mount LEDs. A surface mount LED may have a lens atop the body that
directs the light generated by the surface mount LED outwards.
While the body and the lens of the surface mount LED may radiate
heat, its tabs as well as the thermal shoe on the bottom surface
assist in conducting heat to the mounting surface (e.g., circuit
board) and thus may provide advantageous heat dissipation
capabilities, particularly as compared to non-surface mount LEDs
which tend to dissipate heat typically through their leads. Use of
surface mount LEDs provides a larger and more direct heat
conduction path to the mounting surface (e.g., circuit board), and
may also provide advantages in ease of fabrication and improved
durability.
[0111] In various embodiments as described herein, the lamp
elements used in a lighting effects system or lighting apparatus
may comprise high output semiconductor lights such as, for example,
high output LEDs. Such high output LEDs are available from Lumileds
Lighting, LLC of San Jose, Calif. under the product brand name
Luxeon.TM.. High output LEDs are presently available in white as
well as colors such as green, blue, red, amber, and cyan, are fully
dimmable, and generally operate at about one to several Watts
(e.g., 5 Watts), outputting in certain devices approximately 24 or
more lumens per Watt. The high output LEDs may be mounted upon,
e.g., a metal printed circuit board (PCB) such as an aluminum core
circuit board. High output LEDs may be used in connection with any
of the embodiments previously described herein, and may provide
advantages of increased lighting output with fewer lamp elements
and, hence, reduced cost of construction in certain cases. However,
the driving circuitry for the high output LEDs would generally need
to have a higher output rating than the circuitry used for lower
power LEDs.
[0112] FIG. 17 is a generalized diagram of an array of LEDs 1602
mounted atop a circuit board 1604, as may be used in various
embodiments as described herein. The circuit board 1604 may
comprise rigid fiberglass or phenolic planes with electrically
conductive tracks etched on them, and/or may be metallic in nature
(such as aluminum core PCBs). The term "circuit board" as used
herein is meant to encompass the foregoing structures as well as
various other types mounting apparatus, including flexible
electrical interconnects such as conductive membranes made on thin
Mylar, silicone, or other similar materials. The surface mount LEDs
1602 may be connected together in series and/or in parallel by
electrical traces 1603 on the circuit board 1600. While the LEDs
1602 are illustrated in FIG. 17 as being in a straight-line array,
other LED patterns may also be utilized. As previously mentioned,
the tabs and thermal shoe on the bottom each of the surface mount
LEDs 1602 generally assist in conducting heat to the circuit board
1604, thus providing advantageous heat dissipation
capabilities.
[0113] A lighting apparatus may conveniently be packaged in the
form of a kit that includes a number of components providing
increased convenience, flexibility, and adaptability to operators
in the field. For example, a lighting apparatus kit may include one
or more lighting panels 702, as well as one or more battery units
830 (and/or battery adapters such as described previously herein),
power jumper cable (for connecting the power between the panel(s)
702 and battery unit(s) 830, an AC adapter and power/recharging
cable, one or more lenses 1210, a set of colored or diffusion gels
1259 of various tints and hues, or providing light shaping or
diffusion (such as with a Fresnel lens or holographic lens), and/or
one or more compact mounting stands (or other accessories described
herein), all of which can be packaged conveniently in a portable
case. The colored or diffusion gels may be integrated with a panel,
or else detachable.
[0114] The lighting apparatus and/or battery unit may have
electronics which also provide increased performance, versatility,
and/or flexibility.
[0115] FIG. 18 is a functional block diagram illustrating an
example of circuits or components of an LED-based light panel 1800,
as may be constructed in accordance with, e.g., light panel 702 or
802 described elsewhere herein. The LED-based light panel 1800 in
this example includes a power regulator 1810 which preferably
provides a relatively constant or stabilized current output to one
or more arrays or series of LEDs 1840 (or other semiconductor light
elements). Details of possible embodiments of a power regulator
1810 are described in U.S. Pat. No. 7,569,996, entitled
"Omni-Voltage Direct Current Power Supply," hereby incorporated by
reference as if set forth fully at this point. The power regulator
1810 preferably includes a switched power supply 1820 under control
of a control circuit 1825, such as a PIC microcontroller 1825. The
switched power supply 1820 may be a buck/boost power supply, or
else simply a buck or boost power supply, or other type of power
supply. A buck/boost power supply allows the most flexibility, in
that the input voltage could vary over a relatively wide range; a
particular example is described in application Ser. No. 10/708,717
referred to above. A voltage sense circuit 1831 and current sense
circuit 1832 provide feedback information to the PIC
microcontroller 1825, which information is used in maintaining the
output current to the LEDs 1840 at a stable level, and thereby
reducing undesirable artifacts such as flicker.
[0116] In FIG. 18, a dimmer switch 1826 adjusts a potentiometer or
variable resistor 1835, which in turn provides a dimming control
input signal 1837 to the power regulator 1810. In a preferred
embodiment, the dimmer control input signal 1837 adjusts the level
of gain in a feedback loop for the PIC microcontroller 1825, thus
allowing adjustment of the amount of output current for the LEDs
1840. The circuitry of FIG. 18 can allow, for example, the
adjustment of light intensity without a substantial change in the
output color temperature of the light source (i.e., the LEDs), and
again, without flicker even at relatively low light output levels.
These can be significant advantages to those working in the
field.
[0117] The battery unit 830 described previously herein may take on
various different forms and configurations. In alternative
embodiments, for example, the battery unit 830 may, for example,
comprise one or more "standard" or conventional camera batteries,
as may be obtained by companies such as, e.g., Sony, Panasonic,
Canon, and the like. A preferred battery compartment will include
an adapter panel for receiving at least one attachable battery,
such as a DV ("digital video") battery. A DV type battery typically
has a battery casing designed to be snapped directly into the
camera, although DV batteries may differ from camera manufacturer
to manufacturer. The adapter panel is preferably constructed to
mate to a particular type or brand of battery, and thus different
adapter panels may be made available, each suited to a particular
battery or family of batteries. At least some DV batteries output
less than 12 volts--for example, a typical output voltage is 7.2
volts. The battery unit may comprise two receptor plates each
adapted to securably attach a battery to the adapter panel.
Electrical contacts provide electrical connection from the battery
to downstream electronics or a power output source. The battery or
batteries may be electrically connected in series via electronics
integrated in the adapter panel, thus doubling the voltage to,
e.g., 14.4 volts. Alternatively, the adapter panel could include a
transformer of other type of DC-DC conversion circuitry to step up
the voltage to 12 volts or some other appropriate level.
[0118] The battery unit will preferably include struts or other
attachment means in order to allow the battery unit to readily
attach to, e.g., an LED based light panel 802, in a manner similar
to the way in which battery unit 830 may connect to the panel
802.
[0119] Finally, FIGS. 19A and B illustrate some logic suitable for
use with the preferred embodiment of the instant invention. More
particularly, such operations as are illustrated in FIG. 19 might
be implemented within microcontroller 626, controller 1825, etc.
Procedure 1900 is designed to prepare the instant light to fire in
burst mode upon receipt of a signal from an associated camera or
other electronic device. As a first preferred step 1905, the
instant routine will preferably initialize its variables according
to methods well known to those of ordinary skill in the art. As a
next preferred step, a comparator reference value will be selected
(step 1910). In some preferred embodiments, a comparison will be
made between the voltage in the capacitor that will be used to
power the flash and a reference voltage that might be, for example,
found within the microprocessor. In some preferred embodiments, a
voltage divider will used to make the voltages between the
capacitor (which might be, for example, 50 volts or so) and
microprocessor (e.g., five volts) comparable. That being said,
those of ordinary skill in the art will recognize that this is only
one method of implementing this step and other methods such as A/D
conversion, analog circuitry, etc. could be used instead of a
voltage divider. Additionally, those of ordinary skill in the art
will realize that discrete circuitry equivalents of the operations
in 19A and 19B could readily be constructed by those of ordinary
skill in the art.
[0120] Next, and preferably, a loop will be entered, a purpose of
which is to build up a reservoir of power for use by the LED array
when a flash or burst is requested. As is indicated in FIG. 19B,
preferably the boost transistor will be activated (step 1915) and
then deactivated (step 1920), thereby incrementally charging the
flash capacitor. Next, and preferably, a comparison will be made
between the reference voltage and the voltage in the flash
capacitor (step 1925) and if the comparator is "low," the preferred
logic would branch back to step 1915, where additional power will
be added to the flash capacitor. However, if the comparator is
"high", (i.e., the "yes" branch of decision item 1925), the instant
invention will then preferably proceed to turn on the IRQ (i.e.,
interrupt request line), step 1932.
[0121] Next, the instant invention will next preferably loop
continuously checking for a low state of the comparator (decision
item 1935), thereby allowing for the possibility of leakage in the
capacitor and correcting same if it occurs. If the comparator "low"
value is "no," the instant invention will stay in its current loop.
However, if the decision item 1935 returns a value of "yes," the
instant invention will preferably branch up to step 1950 where
additional power will be added.
[0122] Then, when a sync signal is sensed (or if a photographer
manually activates the flash mode), in a preferred arrangement an
interrupt will be generated that transfers control to routine
1950.
[0123] As a first preferred step in that routine, the output to the
LED will be activated, thereby transferring power from the
capacitor to the LEDs and activating them (step 1950). Next, and
preferably, a timer will be set for a predetermined period of time
(step 1955). Although many different time periods might be used
(including variable time intervals that would be responsive to
through-the-lens metering requirements), in a preferred embodiment
the timer will be set to 0.01 seconds. This is the length of time
the LED array will be activated and, hence, the duration of the
flash.
[0124] Step 1960 is a decision item that is designed to implement
the timer value set in the previous step. Until the timer value is
reached, the LEDs will remain activated and decision item will keep
looping. Once the appropriate period of time has passed (i.e., the
"yes" branch of decision item 1960), the output to the LED will be
terminated (step 1965), thereby ending the flash. Next, and
preferably, the IRQ will be turned off (step 1970) in preparation
for a return to the procedure 1900 or some other procedure in the
software of the instant invention (step 1975).
[0125] Upon return to procedure 1900, the voltage across the
capacitor will dip well below the threshold due to the energy
delivered to flash the LEDs. Thus at decision 1935, control will
return to step 1915 to toggle the boost transistor and recharge the
capacitor. When accomplished, the IRQ will be re-enabled to allow
another flash to occur.
[0126] Certain embodiments have been described with respect to the
placement of lamp elements (e.g., LEDs) on a "mounting surface" or
similar surface or area. It will be appreciated that the term
"mounting surface" and other such terms encompass not only flat
surfaces but also contoured, tiered, or multi-level surfaces.
Further, the term covers surfaces that allow the lamp elements to
project light at different angles.
[0127] Certain embodiments have been described with respect to the
placement of lamp elements (e.g., LEDs) on a "mounting surface" or
similar surface or area. It will be appreciated that the term
"mounting surface" and other such terms encompass not only flat
surfaces but also contoured, tiered, or multi-level surfaces.
Further, the term covers surfaces which allow the lamp elements to
project light at different angles.
[0128] Various embodiments have been described as having particular
utility to film and other image capture applications. However, the
various embodiments may find utility in other areas as well, such
as, for example, automated manufacturing, machine vision, and the
like.
[0129] Those of ordinary skill in the art will understand that the
term "microprocessor" as used herein should be broadly construed to
include any device that is capable of being programmed including,
without limitation, controllers, microcontrollers, gate arrays,
programmable logic devices ("PLD"), etc. Thus, for purposes of the
instant disclosure the terms "processor," "microprocessor" and
"CPU" (i.e., central processing unit) should be interpreted herein
to take the broadest possible meaning, and such meaning is intended
to include any PLD or other programmable or active device of the
general sort described above.
[0130] While preferred embodiments of the invention have been
described herein, many variations are possible which remain within
the concept and scope of the invention. Such variations would
become clear to one of ordinary skill in the art after inspection
of the specification and the drawings. The invention therefore is
not to be restricted except within the spirit and scope of any
appended claims.
* * * * *